Monero transaction distinguishing features - noncesense-research-lab/archival_network GitHub Wiki

What quantities can be set to unusual or revealing values, increasing risk of transaction linkability?

• Number of ring members - (fixed in Oct 2018)
• Arbitrary fees
• Number of inputs
• Number of outputs
• tx_extra field

To render transactions indistinguishable, IsthmusCrypto recommends fixing all of these to a single value or set of allowed values/multipliers. We should default to limiting the choices, unless there is a specific reason that a particular field must be left unconstrained.

Deviations in any of these quantities with any degree of periodicity can allow blockchain observers to infer that transactions probably originate from the same entity.

Probable spend state/time is heuristically revealed if a transaction with defining features later merges with matching transactions in a multi-input transaction (strong heuristic), or appears as a ring member in a subsequent periodic transaction (weak heuristic if once, strong if multiple occurrences)